Arrangement in apparatus for mechanical nailing

ABSTRACT

Device in a mechanical nailing apparatus including a nail holder to support and guide a nail into position for nailing by means of a nail driver. The device is especially designed for nails (51) which, after being nailed, has at least one laterally expanded anchoring portion (52). The inner cavity of the nail holder (55, 56) intended to receive the nail defines, along part of the nail (51), a guide seat (53) of non-circular section adapted to co-operate complementarily with a guide portion (52) on the nail (51) such that the nail, as it is carried into position for nailing, is given a definitely fixed angle of orientation about its longitudinal axis relative to the nail holder. By positioning of the nail holder, i.e. the nailing apparatus, into a suitable angle for anisotropic materials, e.g. the fibre direction in wood, an expansion nail may be nailed in the angular position where the nail will reach maximum gripping power.

The present invention relates to a means for orienting the turning angleof a nail about its longitudinal axis before driving in the nail bymeans of an apparatus adapted for mechanical nailing. Such an apparatusincludes, on one hand, a nail holder holding the nail in position fornailing and, on the other hand, a nail driver for driving in the nail.

Existing apparatuses for mechanical nailing or nailing by machinecompletely lack means for turning or orienting the nail into a certaindesired angular position about its longitudinal axis and holding thenail in this position prior to nailing. This is a great inconveniencewhen it is a matter of mechanical nailing with expanding nails,especially such expansion nails which, after nailing, exhibit one ormore anchoring portions, i.e. portions of the nail expanded or split outfrom the shaft of the nail inside the material. Especially when usingexpansion nails in non-isotropic materials it is a great advantage toorient the nail into such an angle of orientation relative to thestructure of the material that maximum gripping power is obtained.

A common such case is the use of expansion nails according to theSwedish Pat. No. 7703167-2 for nailing in wood or joining of woodendetails. A portion of this expansion nail, situated adjacent the pointthereof, is deformed outwardly towards both sides. It is obvious thatsuch a nail will take a better hold in the wood and thus attain muchgreater gripping power if the expanding portions extend at right anglesto the wood fibre direction than if they would extend in parallel withthe fibre direction.

By this invention a positioning or orientation means is provided fororienting a nail into such a position of rotation that the nail grippingpower attains a maximum after being driven into anisotropic materials.According to the invention this great advantage is achieved in a mostsimple, cheap and reliable manner in that the inner, nail-receivingcavity in the nail holder defines, along a portion of the nail, a guideseat of non-circular cross-section adapted to cooperate complementarilywith a guide portion of the nail such that the nail will be held in adefinitely fixed angle of orientation about its longitudinal axisrelative to the nail holder.

In preferred embodiments of the invention the guide seat of the nailholder is adapted to guide portions of the nail comprising anon-circular nail head, a bulged portion of an expansion or rivet nailor a wedge or chisel-shaped point. In the latter case the guide seat isan edge seat in the nail holder.

An advantageous means is realized if the nail holder consists of atleast two jaws which are movable outwards from the nail and away fromeach other and are kept resiliently pressed against each other. By thisprotruding nail portions such as the nail head and bulges of a rivetnail may be pushed through the entire nail holder by the nail-driver.

The invention will now be described in detail with reference to theaccompanying drawing, in which:

FIGS. 1 and 2 show examples of two prior art types of expansion nails;

FIG. 3 is a longitudinal section through a nail holder including thenail shown in FIG. 1;

FIG. 4 is a cross-section of the nail holder, taken on line IV--IV inFIG. 3;

FIG. 5 shows the lower part of another nail holder adapted to a nailaccording to FIG. 2;

FIG. 6 is a section through nail and nail holder, taken on line VI--VIin FIG. 5;

FIG. 7 shows, in two relatively perpendicular directions, a nailaccording to FIG. 2, with a specifically shaped point; and

FIG. 8 shows, in two relatively perpendicular directions, correspondingto those shown in FIG. 7, a further nail holder adapted for cooperationwith the nail shown in FIG. 7.

FIG. 1 shows an expansion nail 1 with an anchoring portion 2. The nailis driven into the material 3 to fasten a clip 4, for instance forwiring on a wall.

FIG. 2 shows an expansion nail 5 according to the above-mentionedSwedish patent, as used for joining of two wooden parts 7 and 8. Thenail includes an expansion portion 6 extending outwards on either sideof the nail at right angles to the wood fibre direction.

FIG. 3 shows a nail holder in which a nail 30 of the type shown in FIG.1 lies ready for nailing. The nail head 31 constitutes the guide portionand coacts with a guide seat 32 in the nail holder in a manner to bedescribed in greater detail below. The point of the nail 30 isdesignated by 33. It abuts against, or lies close to the material 34into which it is to be driven.

The nail holder consists of two spring-loaded cheeks or jaws 35 and 36which are movable in outward direction. Above the nail head 31 is a naildriver 37 for driving the nail into the material 34. When the naildriver 37 drives the nail 30 into the material 34 the point 33 of thenail presses aside the jaws 35, 36 and penetrates into the material.After the nail has come into contact with the material it cannot turnabout its longitudinal axis but is non-rotatably oriented relative tothe material. As the driving-in operation continues the nail head 31moves downwards while carrying apart the spring-loaded jaws 35 and 36until the nail comes outside the jaws and is fixed in position. The nail30 may, for instance, fasten a clip designated by 39.

FIG. 4 shows a cross-section of the device on line IV--IV in FIG. 3.From the figure appears how the expansion nail 30 has been brought intothe desired angular position about its longitudinal axis. The nail head31 is defined by two straight edges and two circular arcs situatedtherebetween. The nail head will thus constitute the guide portion ofthe nail with which the complementary shaped guide seat 32 of the nailholder will coact. The guide seat 32 is placed straight opposite thenail head 31 when the nail is in position for nailing and leaves acertain play for the nail head, i.e. for the guide portion 31 of thenail.

The nail 30 can be carried towards its position for nailing by means ofgravity, of a spring, of an air current or the like. During thismovement the guide portion--the head 31--of the nail 30 is carried intothe guide seat of the nail holder 35, 36, where it is brought into thedesired angle of orientation. This introduction into the seat is alsofacilitated by vibrations or other movements in the nailing apparatus.The nail is then kept in starting position for nailing.

FIG. 5 shows a nail holder adapted for a rivet nail 51 to the expansionportion 52 of which is utilized as guide portion. The jaws of the nailholder, designated by 55 and 56, have an inner guide seat 53 forcoaction with the guide portion 52 of the nail 51. The material intowhich the nail is to be driven is designated by 54. The device shown inFIG. 5 corresponds in principle to the device of FIG. 3.

FIG. 6 shows a cross-section of the parts in FIG. 5 taken on lineVI--VI. From the figure appears the substantially ellipse-shapedexpansion portion 52 and the corresponding guide seat 53 in the nailholder 55, 56, having a slight interference with the expansion portion52. As in the device described above with reference to FIGS. 3 and 4,the nail 51 has been brought into a definite, fixed angle of orientationin the nail holder prior to nailing which is carried out by means of anail driver in the manner described above.

FIG. 7 shows the point of a rivet nail 71 as viewed in two relativelyperpendicular directions. In the case shown the point 72 of the nail 71is in the form of a wedge or chisel-shaped portion having two surfaces73, inclined towards one another and an edge 74. The point 72 with theportion 73, 74 constitutes the guide portion of the nail.

FIG. 8 shows in two relatively perpendicular sections the outermostpoint of a nail holder with jaws 85, 86 and a guide seat 87 which isadapted for coaction with the chisel-shaped point 72, 73, 74 of the nailin FIG. 7. The right-hand part of FIG. 8 shows the resilient jaws 85 and86 the inner lowermost portions of which consist of two angularlydisposed planes 82 which form a seat for the chisel-shaped point 72 ofthe nail 71. The seat or edge location 87 constitutes the guide seat ofthe nail holder 85, 86. When the point 72 of the nail rests in the seat87 the nail 71 is oriented in the desired angle of orientation and isready for nailing in the manner described above.

It has been described in the foregoing how expansion nails according tothe invention have been brought into a defined fixed position relativeto the mechanical nailing apparatus. Thus, in order to produce maximumgripping power when driving in nails in anisotropic materials it is easyto turn the apparatus into the desired position relative to thematerial, e.g. with respect to the fibre direction in wood.

In the above examples a nail holder with two jaws has been described. Ofcourse it is possible to use holders having three or more jaws, to givethe guide portion of the nail and the guide seat of the nail holderadapted thereto a triangular or other non-circular configuration or tocarry out other modifications within the scope of the appended claimswithout departing from the inventive idea.

I claim:
 1. A nail holder for supporting and guiding a headed nail intoposition to be driven by a nail driver, the headed nail having alaterally displaced bulged guide portion restricted to a portion of thenail shank adjacent the point of the nail opposite its head, said nailholder comprising:a main body, a nail-receiving cavity defined in themain body of the nail holder, said nail holder being positioned to abutmaterial to be nailed and said nail holder being adapted forsimultaneously holding the nail in the nail-receiving cavity and toorient the nail with respect to the material to be nailed; and said nailreceiving cavity including a nail receiving portion and a guide seatportion of oblong cross-section complementary in shape to the crosssection of the laterally displaced bulged guide portion of the nail, tohold the nail in a definitely fixed angle of orientation about itslongitudinal axis relative to the nail holder and said nail receivingfirst portion being of different and larger cross section than saidguide seat portion to permit the laterally displaced bulged guideportion of the nail to move through said nail receiving first portionand into alignment with said guide seat portion whereby the nail is heldin a fixed orientation when driven by a nail driver.
 2. A device asclaimed in claim 1, wherein the nail holder consists of at least twojaws which are resiliently pressed against each other and movable awayfrom each other in an outward direction.